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1996 (1)
1Author    Tetsuaki NishidaRequires cookie*
 Title    Verification of the " Tg-A Rule" in Potassium Silicate and Sodium Tungstate Glasses  
 Abstract    A linear relationship exists in oxide glasses between glass transition temperature (T g) and quadrupole splitting (A) of Fe ,+ . DTA and Mössbauer measurements of silicate and tungstate glasses yielded large slopes of 680 and 260 °C/(mm s~ 1) from the slope of the straight lines when Fe 3+ occupied, as network former (NWF), distorted tetrahedral Si 4+ and distorted octahedral W 6+ sites, respectively. This linear relationship, named a 'T g -Z\ rule", suggests that F e is in proportion to the distortion of NWF-oxygen polyhedra and a higher activation energy is required for the fragments of glass to have a cooperative movement in the supercooled liquid state. The rule" was also valid in the case of potassium silicate glasses heat treated at the temperature close to 7g, indicating a distortion of Si0 4 and Fe0 4 tetrahedra. Substitution of Fe 3+ for individual NWF in silicate and tungstate glasses was confirmed from the Fourier transform infrared (FT-IR) spectra because only the absorption bands due to Si and W were respectively observed without the bands due to Fe. 
  Reference    Z. Naturforsch. 51a, 620—626 (1996); received November 2 1995 
  Published    1996 
  Keywords    Mössbauer effect, silicate glass, tungstate glass, glass transition temperature, quadrupole splitting 'T g -_\ rule" 
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 TEI-XML for    default:Reihe_A/51/ZNA-1996-51a-0620.pdf 
 Identifier    ZNA-1996-51a-0620 
 Volume    51